| Concept definition: |
A 3-hourly quasi-logarithmic planetary index of magnetic activity, representing a value measuring the two horizontal (x,y) components of the <MAGNETIC_FIELD> at a specific solar electromagnetic flux <OBSERVATION_STATION> on the <EARTH>; magnetic field K. K = 0 represents a 2,5 nanoTesla variation from the quiet day value, and K = 9 represents a 666 nanoTesla variation. |
